Programming and CS - Getting Started

We are developing bootcamps on the most important topics and skills that are used throughout our courses. These can be used by incoming undergraduate students to get a head start, incoming graduate students to review, or current students to refresh/remediate.

Programming Bootcamps

Python

Getting started with Python and this bootcamp.

1. Follow along this tutorial -
2. Work on solving these problems - https://www.hackerrank.com/domains/python
3. Get Python installed on your computer -
4. If you are a current or incoming ISU student, or an ISU alumni, sign up for the ISU CS Mattermost, go there to get help.

Using Linux, CS Systems

Reading

To begin with, read through - Linux Tutorial

System Setup

Next, you need to have a Linux system that you can use.

ISU CS Account

If you are a student in a CS course at ISU you will be given an account on the CS linux systems (see CS Accounts and CS Lab Computers).

Linux on Your Computer

You can also download and install VirtualBox on your computer, download a Linux install image (e.g., Ubuntu Linux), and then install Linux into your virtual box.

Mac OS X

You can also use a Mac OS X computer - most (but not all) commands are the same on Linux and Mac OS X. On Mac OS X, to get to the terminal you click on Finder, then Applications, then Utilities, then Terminal.

Try it Out

Once you have your Linux system to try out, open up the terminal (also called the shell, or command prompt), and you are ready to try out some commands. Note that all commands in Linux are case-sensitive. Also, _ is different than -, and ' is different than ".

System Information, Part 1

The following are some commands to print information about the system.

• uptime - how long since last system reboot
• df - information about disk free space
• whomi - which user is currently logged in on the terminal
• hostname - what computer are you currently running commands on
• pwd - which directory are you inside of
• clear - clear the terminal screen

Here is an example session from running on the CS server using all of these commands. Note that the part "cs299@cs:~>" is a prompt that is printed by the terminal, and the part after this is what was typed by the user. So for the first command, the user typed the command uptime and then pressed enter. The system then printed some information on the next line, and then printed the prompt "cs299@cs:~>" again to indicate it is ready for the next command.

cs299@cs:~> uptime
 09:00:45 up 56 days, 19:35,  3 users,  load average: 0.32, 0.31, 0.32
cs299@cs:~> df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/root      1016G  229G  778G  23% /
devtmpfs        498G     0  498G   0% /dev
tmpfs            32M  2.3M   30M   8% /run
tmpfs           498G  8.0K  498G   1% /dev/shm
cgroup_root     8.0M     0  8.0M   0% /sys/fs/cgroup
/dev/sda2       127G   22G  105G  17% /usr
/dev/sda3       127G  8.3G  118G   7% /var
/dev/sda4        64G   13G   51G  20% /tmp
/dev/sda5        10T  2.8T  7.2T  28% /u1
/dev/sda6       4.0T  685G  3.3T  18% /net
/dev/sda7        18T  6.9T   11T  40% /store
cs299@cs:~> whoami
cs299
cs299@cs:~> hostname
cs.indstate.edu
cs299@cs:~> pwd
/u1/class/cs299

Text Editors, Part 1

One thing programmers need to do is edit text files. The text files could be your programs, or they could be data files. There are many different text editors that are normally installed on Linux systems. The most popular are - vim, emacs, nano.

nano is among the easiest text editors to use, so let's get you started using nano. You first need to be logged into Linux and open a terminal. Type the following

nano hello.txt

You will now be running the nano editor and editing a file named hello.txt. Note that the interface is completely text-based. There is nothing for you to click on. Instead of clicking on menus, you have control codes that you can type to save, close, etc. The bottom of the screen lists the control codes that you can use. Each control code is typed by holding down the control key on your keyboard and then pressing a letter.

For example, hold down control and press x to Exit nano. You can type nano hello.txt again to open the nano editor again.

Now type some text, for example "Hello World". You can save your file by holding down control and pressing o. When you do this, nano prompts you to ask what the name of the file should be; you can leave it alone as hello.txt and press enter. Your file is now saved! You can type more into your hello.txt file if you wish. Use the arrow keys on your keyboard to move around inside of your text file. When you are done editing, use control-o to write out (save) your file, and then use control-x to exit nano.

Files and Directories, Part 1

With the terminal you can create, copy, move, and delete files and directories. The following are the most important commands to do this.

• cd - change directory
• mkdir - make a new directory
• ls - list directory contents
• cp - copy files
• rm - remove files (be careful, there is no recycle bin or trash - once you delete, it's gone)
• rmdir - remove directory
• nano - simple text editor

And here is a transcript of the use of these commands on the CS server.

cs299@cs:~> pwd
/u1/class/cs299
cs299@cs:~> mkdir new-dir1
cs299@cs:~> mkdir new-dir2
cs299@cs:~> nano hello.txt
cs299@cs:~> ls
bin/  hello.txt  new-dir1/  new-dir2/  proto/
cs299@cs:~> cp hello.txt new-dir1
cs299@cs:~> cp hello.txt new-dir2/hello2.txt
cs299@cs:~> ls new-dir1
hello.txt
cs299@cs:~> ls new-dir2
hello2.txt
cs299@cs:~> mv new-dir2 new-dir3
cs299@cs:~> ls
bin/  hello.txt  new-dir1/  new-dir3/  proto/
cs299@cs:~> rm hello.txt 
cs299@cs:~> ls
bin/  new-dir1/  new-dir3/  proto/
cs299@cs:~> rmdir new-dir3
rmdir: failed to remove 'new-dir3': Directory not empty
cs299@cs:~> rm new-dir3/hello2.txt 
cs299@cs:~> rmdir new-dir3
cs299@cs:~> ls
bin/  new-dir1/  proto/